Digital optical disc with writeable regions and optical disc player for reading the writeable regions

ABSTRACT

An improved digital optical compact disc is disclosed which incorporates a further information storage element or area for storage and retrieval of track play selection information. The further storage area is comprised of defined information containing regions whose shading or alteration by the user indicates whether a corresponding track is to be skipped or played. An improved compact disc player reads the information containing defined regions and is capable of automatically selecting particular tracks for play. The information contained in the defined regions is stored in a format which is at-once visually-recognizable, machine-readable and manually-alterable.

This is a continuation of application Ser. No. 08/626,674 filed Apr. 2,1996, now U.S. Pat. No. 5,646,420 which is a continuation of Ser. No.08/367,709 filed Jan. 3, 1995, now abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to the field of digital opticalcompact disc information storage devices and, more particularly, thepresent invention relates to an improved compact disc storage devicewhich incorporates at least one further storage element or area forstoring additional information in a format which is both visuallyrecognizable and machine readable. The information in a preferredembodiment is related to selective retrieval and/or identification ofparticular information contained in the compact disc. A correspondingdisc player which is capable of reading both the information digitallystored in the compact disc as well as the information which is containedin the further storage element or area is also disclosed.

2. Description of the Related Art

Conventional digital optical compact discs are generally known in theart and provide a reliable and convenient mechanism for storing andretrieving information. In conventional optical discs, information isstored digitally, usually on a single side of the disc. A plurality ofholes or pits in the surface of the disc define the stored information,and a laser beam is used to scan the surface of the disc to provide anoutput representative of the stored information. While theseconventional systems generally provide satisfactory information storageand retrieval capability, these devices and the systems which access thestored information would be greatly improved by a system which iscapable of repeatedly retrieving a selected portion of that informationonce the selected information has been initially identified or selected.The ability to maintain information related to the selection and/orretrieval of particular information contained in the disc, on the disc,would greatly enhance the performance of existing systems and increaseoverall consumer satisfaction with digital optical compact discproducts.

The shortcomings of conventional compact disc storage and retrievalsystems are apparent from the manner in which information is currentlyselected for playback in these systems. In conventional compact opticaldiscs and in particular those optical discs which contain audioinformation such as music, the sound information is digitally stored inread-only format by the disc manufacturer. In optical compact discswhich contain sound recordings, each individual selection is stored in aseparate location called a track and each track is designated by a tracknumber. The sound recording stored in the particular track is usuallyidentified by its title and artist either by pre-printed material on thedisc or in material which accompanies the disc. In these systems, thedisc user can only read the information stored within the disc with acompact disc player and the user typically is not able to storeadditional information on the disc. When a user selects a particularcompact disc containing the desired information or sound recording whichthe user would like to hear, the user must either listen to all of theselections on the disc or manually enter programming information intothe compact disc player identifying the particular track or tracks whichthe user would like to hear.

Most conventional compact disc players are capable of playing selectedrecordings from digital optical compact discs. These disc players allowthe user to program his or her track preferences into the machine sothat the machine may skip undesired selections and play only thosetracks or selections which the user wishes to hear. The track selectioninformation is typically temporarily stored in a memory of the playerwhile the disc player proceeds to play the selected tracks from theparticular disc. In conventional compact disc player systems which arecapable of playing selections from more than one disc at a time, theuser is generally able to choose from the various selections on each ofthe discs which are inserted into the player by identifying the discthrough its position in the player and then subsequently identifying theparticular tracks which the user wishes to hear. (e.g., a user mayselect the desired track for play as follows: disc number 1, tracking,7, 10; disc number 2 tracks 3, 5, 8, etc.) These conventionalprogrammable disc players require relatively complex programming stepswith which the user must become familiar with in order to select theparticular tracks on the disc or discs which the user wishes to hear.

One of the problems with these conventional systems is that a person whodesires to hear only particular selections from a given disc is requiredto use the disc player as an interface for making the selections, andthe selection information is lost once the disc player has played theparticular selection s! or after the machine is turned off. As noted,the selection programming process for these systems can be fairlycomplicated especially in systems which are capable of playing a numberof discs at a time. Additionally, this process must be repeated eachtime the user would like to listen to a particular disc after it hasbeen removed from the machine because the selection information is notmaintained with the disc.

It has been recognized, however, that in most instances, the particulartrack or track selections which the user initially identifies forplaying from a particular compact disc are the same selections which theuser will select at a later time so that the ability to maintain theselection information is therefore desirable. This is due to the factthat most digital optical compact discs, like most albums, have fillermaterial which most listeners usually do not enjoy hearing or a personusing a compact disc system may have certain favorite selections from adisc which they particularly enjoy.

One proposed solution to the problems identified above is disclosed inU.S. Pat. No. 4,872,151 invented by Smith. This reference describes aconventional digital optical compact disc having a magnetic storageelement in the form of a magnetic strip for storing order of play datafor the compact disc. The magnetic strip is attached to the disc and theorder of play data stored in the magnetic strip can be maintained withthe disc. Although the solution proposed by Smith addresses some of theproblems identified in the art, the Smith disclosure has numerousdisadvantages.

First of all, the apparatus disclosed in Smith requires that a personusing the system interface with the compact disc player system in orderto identify the selection information for a particular disc. As noted,this process can be fairly complex especially for systems in which anumber of discs may be programmed at the same time for play.Additionally, because the selection information is stored magneticallyon the disc, there is a significant risk that the selection informationcould be inadvertently lost due to accidental contact with the magneticmedia or by exposing the magnetic media to a magnetic field. The systemdisclosed in Smith is also undesirable because the selection informationis not readily ascertainable from viewing the surface of the disc. Inorder for a person using the system disclosed in Smith to determinewhich selections have been selected for play on a given disc, the personmust insert the disc into the disc player so that a magnetic head in thedisc player can read the magnetically stored track selectioninformation. One further disadvantage is that the system disclosed inSmith requires fairly complex additions to existing disc playercircuitry for implementation, most notably, the Smith design requiresthat magnetic read and write heads be incorporated into the disc playeras well as fairly complex software for control of the magnetic heads inorder to write information to the disc and read information from thedisc.

Thus, there remains a need in the art for a compact disc and disc playersystem which is capable of maintaining compact disc selectioninformation along with the disc in a non-volatile format which is atonce machine readable, visually recognizable and manually inscribablewithout the use of a player.

Accordingly, it is an object of the present invention to provide afurther information storage element or area on conventional digitaloptical compact discs which allows user selection information to bemaintained in non-volatile format on the disc.

It is a further object of the present invention to provide a system forautomatically reading and controlling a disc player via selectioninformation stored on a digital optical compact disc.

It is another object of the present invention to provide a simplemechanism by which a person may manually select particular tracks on acompact disc for playing without the use of a compact disc player.

It is another object of the present invention to provide a storagemechanism for the track selection information which is both visuallyrecognizable and machine readable.

It is a further object of the present invention to provide a design forreading disc selection information which is both simple to use andeconomical to implement.

It is a further object of the present invention to provide a furtherstorage element or area on conventional digital optical compact discswhich is compatible with existing optical discs and which may be easilyapplied to existing discs.

Other objects and advantages of the present invention will becomeapparent from the following summary of the invention, the drawings, andthe detailed description of the presently preferred embodiments.

SUMMARY OF THE INVENTION

The present invention eliminates the need for the user of a conventionalcompact digital audio disc to re-program a disc player with userselection information each time the user desires to access a particularselection or a number of selections from a given compact disc. Theselection information is manually entered on the disc in a non-volatileformat without the aid of the disc player. In a preferred embodiment,the additional information is recorded on the compact disc in a formatwhich is both visually recognizable and machine readable. Theinformation is stored on the same or opposite side of the disc as theoptically recorded data but is located in an area which does not containthe read only optically stored data.

Most conventional compact discs have a centrally located region adjacentto the central aperture of the disc which does not contain informationand which is suitable for locating the additional information storagearea or element. Furthermore, currently all CD's are single sided, theupper surface being reserved for user-readable pre-printed data,graphics, etc. In a preferred embodiment, the disc selection storageelement is comprised of defined information containing areas which areeither light or dark in appearance so that a device such as anopto-interrupter which passes over the defined areas is able todetermine whether or not the defined area is shaded or otherwisemanually differentiated from its surroundings. The opto-interrupter"reads" the shading of the defined area and provides a digital outputwhich indicates whether the defined area is either light or dark inappearance. Each defined area is associated with a corresponding audiotrack on the disc and the digital output from the optical interrupterfor a corresponding defined area of a track determines whether or notthe disc player will skip or play the particular track.

It is preferred that the defined information containing areas beradially located around the central aperture such that the center ofeach area is located at substantially the same distance from the centerof the disc as are the others. This arrangement allows a singleopto-interrupter to read each of the defined areas as the disc playerspins the disc. One defined area, referred to as the synchronizationregion, is larger than each of the remaining defined areas in order toprovide a synchronization pulse which is used to identify the relativeposition of the information containing areas on the disc (based on knowntiming information). The status of the first information containingdefined area which passes the opto-interrupter after the synchronizationregion, determines whether the player will skip the first track on thedisc and the status of each of the remaining defined areas whichsubsequently pass the opto-interrupter determine whether each of theircorresponding subsequent tracks will be skipped or played.

Once the disc spins up to speed, the opto-interrupter looks for thelargest reflective area which corresponds to the synchronization markeron the disc. Because the disc controller is aware of the rotationalspeed of the disc and label it therefore knows the approximate expectedduration in system clock cycles for the synchronization pulse on thedisc. Once the controller finds the synchronization pulse based on theduration of the signal from the opto-interrupter, the locations of eachof the information containing defined areas are then determined withrespect to the trailing edge of the synchronization region and withreference to the disc player system clock. The system is able todetermine this information because each of the defined informationcontaining areas are located at a fixed distance from one another.Although it is known that the rotational speed for conventional compactdisc players is not constant, it is recognized that the changes whichoccur in rotational speeds for the disc are insignificant from onerevolution to the next for the purpose of identifying the location ofthe defined information containing areas. Compact disc controllercircuits are also aware of the instantaneous rotational velocity of thedisc.

The information containing defined areas may either be manufactured intothe disc by the disc manufacturer or they may be added at some timeafter the disc is manufactured. The ability to add the further storageelement or area to existing discs allows the system to be compatiblewith existing discs simply by retrofitting the disc with the additionalstorage element or area. In the preferred embodiments of the presentinvention, the further storage element or area is either comprised of,or located on the surface of an adhesive backed plastic or paper labelwhich may be attached with the adhesive to a principal surface of thedisc, or the further storage element may be comprised of, or located ona hard plastic surface which snap-fits into, over or around the apertureof existing compact discs or alternatively, the defined informationcontaining regions may be incorporated into the disc by themanufacturer.

In the first embodiment, the adhesive backed element is simply attachedto the disc in a portion of the disc which does not contain the soundrecording or other information. The adhesive label is an annular labelwhich matches the area on the compact disc adjacent to the centralaperture which does not generally contain the digitally encoded data orany other available surface on the upper side of the disc. In eachembodiment, the surface of the defined information containing areas areof a composition, texture or structure such that they facilitate manualrecording of selection information. In a preferred embodiment, thecomposition, texture or structure is suitable for receiving alterationor marking from a writing instrument such as a marker or grease pencil.In an alternate embodiment, the information containing defined areas aredesigned to receive tabs which may be added, removed or moved from or onthe disc in order to identify which tracks will be played or skipped.

The user programs a particular compact disc by either removing orapplying a tab to the compact disc or by filling in or erasing thedefined areas on the label associated with the particular track to beskipped. One skilled in the art will appreciate that convention shoulddictate whether a lightened region or a darkened defined regionindicates that a particular track should be skipped or played. Eitherchoice will work equally well and it is understood that it is desirableto have all disc systems operate in a similar fashion so that a personmay play the desired selections on any disc player system whichincorporates the present invention.

In the present invention, compact disc players would be suitablyequipped with an inexpensive opto-interrupter (conservatively a $.50component) and therefore be able to detect the user-programminginformation and subsequently direct the disc player's controllercircuitry to avoid the undesired tracks by issuing a "skip" command. The"skip" command is typically already part of a conventional compact discplayer instruction set.

This improved digital optical compact disc and disc player allows thedisc user to selectively identify particular tracks of a compact discfor play in a format which is both visually recognizable andmachine-readable. The track selection information may be stored alongwith the disc in a non-volatile format and when the disc user wishes tohear the desired selections from the disc, the disc user only needs toinsert the disc into a compatible disc player in order to play thedesired selections. There is no longer a need to reprogram a disc playereach time the user inserts any given disc into any suitably equippedplayer.

A "preferences" switch may also be incorporated within the player inorder to enter enable or disable the preferences. When the preferencesare disabled, the disc player ignores the selection information in thefurther storage area.

Additional features and advantages of the present invention aredescribed in, and will be apparent from, the detailed description of thepresently preferred embodiments and from the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a perspective view of a new and improved optical compact discin accordance with a first embodiment of the present invention whereinthe further information storage area or element is comprised of a singlering of information containing defined areas manufactured into thesurface of a compact disc.

FIG. 1B is a perspective view of a second embodiment of the presentinvention wherein the further information storage area or element iscomprised of a double ring of information containing defined areasmanufactured into the surface of a compact disc.

FIG. 1C is a top plan view of a new and improved compact disc inaccordance with a further embodiment of the present invention whereineach of the information containing defined locations has a centralmarkable region for identifying skip/play information.

FIGS. 2A and 2B illustrate application of the further storage element tothe surface of a compact disc wherein the storage element is embodied asan adhesive backed label.

FIG. 3 illustrates a cross-sectional view of the further storage elementsimilar to that illustrated in FIGS. 2A and 2B as applied to a compactdisc but of a smaller diameter.

FIG. 4 illustrates a cross-sectional view of the embodiment of FIG. 1Awherein the further storage element is manufactured into the surface ofthe disc.

FIG. 5 illustrates a cross-sectional view of the embodiment illustratedin FIGS. 2A and 2B showing the textured surface for the defined regions.

FIG. 6 illustrates a schematic diagram for a typical opto-interrupterfor use with the present invention.

FIGS. 7A-7C illustrate operation of the present invention with respectto an exemplary embodiment and the corresponding output from theopto-interrupter.

FIG. 8 is a block diagram illustration of an improved compact discplayer which incorporates the present invention.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

An embodiment of the present invention is shown generally at 10 in FIG.1A wherein an improved compact disc 12 having an aperture 14 has afurther storage element or area comprised of a ring of informationcontaining defined areas 16 radially surrounding the aperture 14. Eachof the defined areas 16 are located at substantially the same distancefrom the center of aperture 14. The information containing defined areas16 are located in a region of the digital optical compact disc whichtypically does not contain the optically stored information. The ring ofinformation containing defined areas may be applied via an adhesivebacked label or alternatively this region may be attached to a hardplastic base which snap-fits into the center aperture of the disc oradditionally it may be a region which is incorporated into the disc atthe time of manufacture as shown. The width and spacing between each ofthe defined areas 16 is substantially the same in the preferredembodiment so that the spatial relationship may be used to identify thedefined areas as they pass under an opto-interrupter, the operation ofwhich will be described in greater detail below. A shaded area 17surrounds, separates and offsets the defined regions 16. A largersynchronization area 18 is located within the ring of informationlocations 16 at substantially the same distance from aperture 14 as thedefined areas 16. The interval of the synchronization area 18 isapproximately twice as long as that of the defined areas 16 so that itmay be easily recognized as providing a synchronization pulse when thesynchronization region 18 passes the opto-interrupter of a disc playerof the present invention.

FIG. 1B illustrates an alternate embodiment of the present inventionwhich is shown generally at 20. In this embodiment, a compact disc 22having an aperture 24 has a further storage element comprised of tworings of information containing defined areas 26,28 which surround theaperture 24. Outer ring of information containing defined areas 26surrounds an inner ring of information containing defined areas 28.Outer and inner information synchronization regions 30 and 31 are alsolocated within their respective rings. As with the previous embodiment,a shaded region 33 surrounds, separates and offsets each of the definedregions and synchronization regions. It is understood that thisembodiment of the present invention allows greater storage capacity forthe further storage element. In an alternate embodiment one of the ringsmay contain only timing information for defining the locations of theother ring. In this embodiment, as with the embodiment of the presentinvention illustrated in FIG. 1A, the outer and inner rings of definedinformation containing areas 26, 28 are located in a region of the discadjacent to the aperture 24 which typically does not contain the audiodata that is stored on a conventional compact disc. FIG. 1C illustratesa further embodiment, which is shown generally at 34, wherein a compactdisc 35 having a centrally located aperture 36 has a ring of informationcontaining defined areas 38 that surround the aperture 36. Each of theinformation containing locations 38 have inner markable regions 40 whichare surrounded by a darkened border. A synchronization region 41 is alsolocated in the ring of information containing sections as in thepreviously described embodiments. However, in this embodiment, thesynchronization region is shaded so that the synchronization pulse willbe low and the reference point will be based on the rising edge from theoptical reader as will be described in more detail below. As with thepreviously illustrated embodiments of the present invention, theadditional storage element is located in a region of the disc whichtypically does not contain the optically stored data. The arrangement ofthe information containing defined areas in each of the illustratedembodiments allows a single opto-interrupter located in the disc playerto read the status of each of the defined areas on the disc ortwo-opto-interrupters in the case of the embodiment illustrated in FIG.1B. The opto-interrupter "reads" the shading of the defined areas andprovides a digital output which indicates whether the defined area iseither light or dark in appearance. In the preferred embodiment of thepresent invention, each defined area is associated with a correspondingaudio track on the disc and the digital output from the opticalinterrupter for the corresponding defined area of a track determineswhether or not the disc player will skip or play a particular track. Asnoted, the synchronization region is approximately twice the interval ofthe remaining defined regions on the disc and is used to provide asynchronization pulse which is used to identify the positions of theremaining defined regions on the disc. The status of the firstinformation containing defined region which passes the opto-interrupterafter the synchronization region determines whether the first track ofthe disc will be skipped or played and the status of each of theremaining defined areas which subsequently pass the opto-interrupterdetermine whether each of their respective subsequent correspondingtrack selections will be skipped or played.

In the preferred embodiments of the present invention, the furtherstorage element or area is either located on the surface of an adhesivebacked plastic or glossy paper label which may be attached with theadhesive to the surface of the disc or the further storage element maybe attached to a hard plastic base which snap-fits into the centralaperture of a conventional compact disc or alternatively, the furtherstorage area may be incorporated into the disc at the time ofmanufacture. FIG. 2A illustrates the application of an adhesive backedlabel 42 containing an embodiment of the further storage element. FIG.2A illustrates the label 42 prior to application to the surface of disc12. The label 42 is applied to an area which typically does not containthe read-only optically stored data on a conventional digital opticaldisc. As with the previous embodiment, the information containingdefined regions 43 and synchronization region 44 are surrounded,separated and set off by a shaded region 45. FIG. 2B shows a label asapplied to a compact disc. FIG. 3 illustrates a cross-sectional sideview of a small diameter label as applied to the surface of the discshowing the label 42, label adhesive 42' and disc 12. In one embodimentof the present invention, the surface of the defined informationcontaining regions such as 16, 26, 28, 40 and 43 are of a composition,texture or structure which is suitable for receiving marking from amarker or grease pencil or other alteration. The remaining areas of thefurther storage element are smooth so that they may not be readilymarked or altered in order to eliminate stray marks which might degradethe performance of the system. As previously noted, in an alternateembodiment, tabs may be applied to or removed from the definedinformation containing areas in order to store the skip/play informationfor the tracks on the disc.

FIG. 4 illustrates a cross-sectional view of the embodiment illustratedin FIG. 1 showing a possible surface structure for the defined regionswhich have been incorporated into the disc at the time of manufacture.In FIG. 4, the structure of the defined information containing areas isrougher than the adjacent smooth surface of the shaded region 17. Theinformation containing regions 16, 18, 26, 28, 40 and 43 are such thatthey more readily receive the markings from a grease pencil or marker.The roughened surface of the defined information containing areas 43contrasts with the smooth adjacent areas of the shaded portion of thestorage element 17 which do not readily receive markings and the like.FIG. 5 illustrates a close-up cross-sectional view of an alternateembodiment of the device illustrated in FIGS. 2A and 2B showing the disc12, label 42, adhesive 42' and defined region 43 wherein there is alarger diameter for the label. As with the previously illustratedembodiments, the roughened structure of the defined informationcontaining region 43 is apparent from the drawing. It should beunderstood that the alternate embodiments of the present invention whichemploy moveable or removable tabs or the like to define the skip/playinformation for the disk do not necessarily require that the surface ofthe information containing regions 16 be ridged or roughened in order toreceive markings. The tabs could also be attached with a "Post It" typeadhesive thus allowing the tabs to be added to as well as removed fromthe surface of the information containing defined regions. The color ortonality of the tabs only needs to contrast with the typical color orshading of the information containing defined regions. It should also beunderstood that the systems could be mutually compatible whereintextured defined regions are receptive to the adhesive used in the tabsso that someone having only tabs or only a grease pencil could still usethe system, thus increasing the overall usability and compatibility ofthe systems.

FIG. 6 illustrates an embodiment of a photo-interrupter for use with thepresent invention which is shown generally at 60. The photo-interrupterscans the disc with a photodiode 63 which transmits a steady beam oflight onto the surface of the disc 65 where it is reflected ontophototransistor 67 when a reflective surface lies under the beam. Thepresence of light and dark regions at the surface of the disk 65determine whether phototransistor 67 conducts and thus is capable ofproviding a digital output representative of the shading of the surfaceof the disc 65 which lies beneath the photo-transistor 63. Theembodiment of the photo-interrupter shown in FIG. 6 is designed toreflect off the surface of the disc so that the photo-interrupter wouldnecessarily be located above the surface of the rotating disc in acompact disc player which is capable of playing discs having a furtherstorage element in accordance with the present invention. However, itshould be understood that other types of photo-interrupters orlight-sensitive devices are suitable for use with the present invention.Most notably, interrupters which pass light across a gap withoutreflecting off a surface are suitable for an embodiment which passeslight through a transparent portion of an optical disc such as thecentral region of conventional digital optical compact discs. In apreferred embodiment of the present invention, the optical-interrupteris embodied as the GP2S05 or GP2S15 manufactured by Sharp Electronics ofJapan.

FIGS. 7A-C illustrate operation of the present invention with respect tothe further storage element illustrated in FIG. 1A or 2A and 2B. Thefurther storage element 70 is comprised of a darkened region containinga plurality of defined information containing locations 74 numberedconsecutively from 1-6. A synchronization region 78 precedes definedinformation containing locations 74 as they pass under theopto-interrupter 80. FIG. 7B illustrates what the opto-interrupter 80"sees" as the disc rotates beneath the opto-interrupter. Reflection 85corresponds to the output produced by the synchronization region 78 andthe remaining reflections 86, 87, 88 and 90 correspond to the unmarkedregions for tracks 1, 3, 4, and 6 respectively. FIG. 7C illustrates theelectronic output from the opto-interrupter 80. Digital pulse 95corresponds to the output generated by the synchronization region 78 andthe remaining digital pulses 96, 97, 98, 99 correspond to the outputproduced by the opto-interrupter from unmarked tracks 1, 3, 4 and 6respectively. It will be appreciated by those skilled in the art thateach of the alternate embodiments disclosed which employ application orincorporation of the information containing defined regions willfunction in a similar manner. It should also be understood that thescanning aspect of the invention will work just as well if theinformation containing regions are initially shaded dark rather thanlight, however, the use of initially light regions are easier to markwith a grease pencil or the like. The use of oppositely shaded tabs willwork equally as well with either selection. Convention should dictatethe selected format so that all disc player systems will use a similarformat.

In the preferred embodiment, the invention employs the overall disccontroller to execute play of the selected tracks. Because the systemuses the overall system controller, it is aware and capable ofcontrolling the rotational speed of the disc (and label) which is usedin reading the information contained in the defined regions of thefurther storage element. The known period of rotation is first assignedthe value of N clock pulses by the controller. Because:

1 Rotation=N clock pulses

N/360=One angular degree of rotation

N/90=four angular degrees of rotation, etc.

The number N is selected so that it is a whole number of system clockcycles. For example, at the moment that label reading begins; N may beassigned the value of 1440 which is 360×4 or consequently 4 clock cyclesper angular degree of rotation. In the preferred embodiment, asynchronization region which has 16 degrees of arc therefore produces anoutput which is 64 clock cycles in duration (4×16). The 16 degreesynchronization region is followed by an 8 degree border area which isthus 32 clock cycles in duration (4×8); followed by 28 defineduser-markable information containing regions each having 4 degrees ofarc which produce an output for 16 clock cycles and each of theinformation containing defined regions are separated by 28 border areaswhich are 8 degrees wide resulting in a separation of 32 clock cycles(8×4).

The rotational speed of the disc and the spatial relationship of thesynchronization region and information-containing defined regions isthen used to locate the user preference information on the disc. Oncethe trailing edge (or in the case of the opposite colored label, rising)of the 16 degree synchronization pulse passes the detector, theopto-interrupter is then able to read the contents of 28 informationcontaining defined regions. For the sake of accuracy, the system clockis used to trigger a read from the opto-interrupter at the center ofeach information containing defined region thus obviating the potentialfor error from possibly reading an edge of the information containingdefined region which might be poisoned by background color in thedetector's field-of-view while also eliminating the effects of jitter orskew from any shock or vibration transmitted to the rotating disk andlabel.

In the example of the preferred embodiment, a clock period androtational speed are chosen such that there are 1440 clock cycles perrotation upon initiation of reading the user preference information.These numbers have been selected as they are convenient, easilyobtainable, and because they provide a sufficiently high degree ofresolution (4 clock cycles per degree of revolution). The typicalresults for location of each of the information containing definedregions in terms of relative angle and clock cycles to center locationare set forth in Table I below.

                  TABLE 1    ______________________________________    Region      Angular Location    Trailing Edge -                of Center     Clock Pulses To Center    Synchronization Pulse                (Defined as 0 degrees)                              Clock Ref. Reset = 0    ______________________________________    Track Region 1                 10 degrees   40    Track Region 2                 22 degrees   88    Track Region 3                 34 degrees   136    Track Region 4                 46 degrees   184    Track Region 5                 58 degrees   232    Track Region 6                 70 degrees   280    Track Region 7                 82 degrees   328    Track Region 8                 94 degrees   376    Track Region 9                106 degrees   424    Track Region 10                118 degrees   472    Track Region 11                130 degrees   520    Track Region 12                142 degrees   568    Track Region 13                154 degrees   616    Track Region 14                166 degrees   664    Track Region 15                178 degrees   712    Track Region 16                190 degrees   760    Track Region 17                202 degrees   808    Track Region 18                214 degrees   856    Track Region 19                226 degrees   904    Track Region 20                238 degrees   952    Track Region 21                250 degrees   1000    Track Region 22                262 degrees   1048    Track Region 23                274 degrees   1096    Track Region 24                286 degrees   1144    Track Region 25                298 degrees   1192    Track Region 26                310 degrees   1240    Track Region 27                322 degrees   1288    Track Region 28                334 degrees   1336    ______________________________________

The preferred embodiment thus provides an easy procedure through which aconventional compact disc controller is able to read the user preferenceinformation from the defined information containing regions on thefurther storage element. The results are then read into the skip/playmemory or register of the disc player which then proceeds to play onlythe selected tracks from the disc or discs which have been inserted intothe player. Other labels are easily created which have differing numbersof user markable regions.

In an alternate embodiment, the disc player determines the userselection information "on the fly" without first defining the rotationalspeed of the disc. In this embodiment, the disc speed is used to definethe number of clock cycles it takes to pass through the synchronizationregion. Once the disc spins up to speed after it has been inserted intoa disc player, the disc controller in conjunction with the interrupterlooks for the largest reflective area on the disc with reference to thesystem clock and identifies this region by noting that theopto-interrupter puts out a logical "1" for the greatest number ofsystem clock cycles when this portion of the disc passes beneath theopto-interrupter. The disc controller then looks for the secondoccurrence of this region in order to determine the number of clockcycles necessary for one complete rotation of the disc. Once the precisenumber of clock cycles is known for complete rotation of the disc, thecontroller divides this number by 360 degrees to determine the number ofclock cycles per degree. Once this value is determined, the system thendetermines the number of clock cycles to each of the defined informationcontaining locations with reference to the synchronization pulse basedon the known spacing in degrees of each of the defined informationcontaining locations. The system controller then uses the trailing edgeof the synchronization pulse as a reference point to determine at whatpoint in time each of the centers of the defined information containingregions will pass beneath the opto-interrupter. The system controllerthen polls the output from the opto-interrupter at these times in orderto determine whether the information containing region is either lightor dark. This information is used in determining which of the tracks onthe disc the user has selected to play. Similar detection schemes may beobtained via single or dual interrupt methodologies.

In the alternate embodiment of the invention illustrated in FIG. 1C, thesystem uses a similar procedure for locating the defined regions. Insuch a system, the system looks for the longest low output from theopto-interrupter corresponding to the sync pulse and then it locates thedefined regions by timing the duration of each subsequent low output.The defined regions would have a fixed size in relation to thesynchronization region so that the system could use this information tofind each of the defined regions. For example, if the defined regionswere 1/2 the size of the synchronization region, the system would checkto determine whether the next low output had a duration greater than 1/3the number of clock cycles for the duration of the synchronizationpulse. If the next low out had a duration greater than this value, itwould know that the defined region had been marked and would set thecorresponding location in the skip register accordingly. The 1/3 valueis selected to allow for timing errors in the system. (i.e. the systemshould look for a low value which is sufficiently greater than theduration of the low created by the border surrounding the defined regionbut which is also sufficiently lower than the low value corresponding tothe duration of the complete defined region) The above values shouldadequately provide for any errors inherent in the system. If the nextlow following the synchronization pulse is less than the 1/3 value, itknows that the defined region has not been marked and will not time thenext low (corresponding to the opposite border of the defined region)but it will examine the second low which corresponds to the leading edgeof the next defined region. The system performs a similar evaluation ofthe remaining defined regions and loads appropriate values in thecorresponding locations in the skip register accordingly. The skipregister is a memory in the disc player which has memory locationsassociated with each of the tracks on the disc and which containsinformation defining whether each of the tracks on the disc will beskipped or played. The skip register is typically a volatile memory.

An improved digital optical disc player which incorporates the presentinvention is shown generally at 110 in FIG. 8. A disc player controller,112 is connected to a defined information containing region scanner 114and the disc player spindle motor 116. As previously discussed, thecontroller 112 operates in conjunction with the scanner 114 to determinewhich tracks on the disc will be selectively played. The disccontroller, then operates in conjunction with the digital optical beamcontroller 122 to appropriately position the digital optical beam reader119 via the optics motor 118 accordingly. Thus, only selected tracks aretransmitted to the audio amplifier 120.

It will also be understood that as an alternate approach, slidable orotherwise movable plastic tabs may be used to define the informationcontaining areas. Furthermore, any other visually recognizable, manuallyalterable mechanism will work equally as well. It is also contemplatedthat in the embodiment which employs adhesive labels or the like, thelabel may include a centrally located depressed region or embossmentcorresponding to the central aperture on the disc. The depressed regionis used to properly position the label in the center of the disc and maybe subsequently removed once the label is adhered to the disc. With sucha device, the user simply positions the depressed central region in thedisc aperture with his finger thereby ensuring rough concentricity ofthe lable to the central aperture of the disc. Alternatively, a simpletool having a platform to receive the label and a central cone whichfits into the disc aperture for axially aligning the label to the discmay be used. In addition to using the further storage element or areafor selective play of tracks on a disc, the information stored in theregion may also include information related to classification of thetype of disc. For example, in multiple disc players, a user may usecertain of the defined information containing defined regions toclassify the material on the disc. For example, the "code" 101 (light,dark, followed by light) might indicate a particular type of music. Theuser would be able to then select only the discs in the machine with theparticular user classification. The machine would then select for playonly those marked tracks on discs which have the appropriateclassification.

The present invention is subject to many variations modifications andchanges in detail. It is intended that all matter described throughoutthe specification an shown in the accompanying drawings be consideredillustrative only. Accordingly, it is intended that the invention belimited only by the spirit and scope of the appended claims.

I claim:
 1. A digital optical disc comprising:first and second sides anda center; and a plurality of defined regions containing informationwhich is simultaneously both human and machine readable, saidinformation being in a format which is manually alterable and located onthe first side of the disc; at least one further defined regioncontaining synchronization information, said further defined regionlocated substantially at a same radial distance from a center of thedisc as the plurality of defined regions; wherein said information isused to selectively access digitally encoded audio data stored on thedisc.
 2. The optical disc of claim 1, wherein said synchronizationfurther defined region is in a format which is substantially notmanually alterable.
 3. A method of selecting a portion of audioinformation contained on a digital disc comprising the steps of:a)providing a digital optical disc comprising a plurality of definedregions containing information which is simultaneously both human andmachine readable, said information being in a format which is manuallyalterable and located on a first side of the compact disc, wherein saiddisc further comprises at least one further defined region containingsynchronization information; b) generating a first digital outputrepresentative of information contained in at least one of the pluralityof defined regions by scanning the first side of the disc with a singlescanner electrically connected to a disc player; and c) retrievingselected audio information from the disc based on the first digitaloutput.
 4. The method of selecting a portion of data contained on adigital disc of claim 3, wherein said synchronization defined region islocated substantially at a same radial distance from a center of thedisc as the plurality of defined regions.
 5. The method of selecting aportion of data contained on a digital disc of claim 3, wherein theplurality of defined regions containing information are adjacent to oneanother and form a fist annular ring of spaced apart defined regionssurrounding a center of the disc.